The Bite of Blood Safety: Environmental Health II PDF (2024)

The Bite of Blood Safety: Environmental Health II NOVEMBER 5, 2024 The Bite of Blood Safety “In the summer of 2002, Ontario and Quebec experienced an epidemic of West Nile virus, associated with bites from mosquitoes. The public became very concerned that they were at risk of infection...

The Bite of Blood Safety: Environmental Health II NOVEMBER 5, 2024 The Bite of Blood Safety “In the summer of 2002, Ontario and Quebec experienced an epidemic of West Nile virus, associated with bites from mosquitoes. The public became very concerned that they were at risk of infection, and that the West Nile virus could be transmitted through the blood supply. To avoid recurrence of experiences with blood-borne transmission of human immunodeficiency virus (HIV) and hepatitis C, Canadian and US blood systems pushed for the development and implementation of a costly nucleic acid amplification testing (NAT) program to screen potential blood donors for West Nile virus. This case addresses several policy issues, including: role of evidence, framing of issues, screening, policy trade-offs, cost-effectiveness analysis, ethics (precautionary principle), and federal-provincial roles and responsibilities”. (Deber and Mah, 2014) Agenda A bit more Environmental Health… Vector Borne Disease Primer Blood safety and the Krever Commission (1997) Framing Public Health and the Naylor Report (2003) The Precautionary Principle Risk Management Science & FMEA Cost Effectiveness Analysis Ethical decision making Related/Support readings in Chapter 1 2.1.3 Federal vs. Unitary models 2.2.1 Federalism in Canada: The Constitution Act, 1867 3.4 Framing 3.6.2 The Precautionary Principle 6.3.1 Public Health 7.2 Canada Health Act 8.1 Economic Analysis: Cost-effectiveness 8.2 Screening  Learning Objectives To understand the importance of VBD and blood safety To summarize the importance of the Krever Commission and the Naylor Report in blood safety matters and beyond To identify how framing leads to selection of policy instruments To understand where the term “precautionary principle” was derived and how it helps to shape selection of policy instruments and implementation To summarize how risk management science and the precautionary principle can be used in public health policy To differentiate between cost-effectiveness and cost-utility analyses To define the ICER and how it is used in combination with the Cost- effectiveness plane  Relationship between people and environment What is Environmental Health? Systems-based, ecological approach “The theory and practice Others focus on environmental conditions, of assessing, correcting, controlling hazards or health-promoting controlling and preventing environments those factors in the environment that can potentially affect Chemical and physical hazards adversely the health of present and future generations” (WHO) Social and built environments Naylor Report (2003): Emerging Infectious Diseases, Globalization, and Bioterrorism COVID is only the most recent example of emerging infectious diseases - diseases that are newly identified, or that have existed previously but are increasing in incidence or geographic range. Since 1973, more than 30 previously unknown diseases associated with viruses and bacteria have emerged: Ebola virus (1977) Legionnaire's disease (1977) E. coli 0157:H7- associated hemolytic uremic syndrome (1982) HIV/AIDS (1983) Hepatitis C (1989) Creutzfeldt-Jakob disease (1996) H5N1 Influenza A or avian flu (1997) West Nile virus infection (2002) SARS (2003) H1N1 (2009)  General VBD Overview Vector-borne diseases (VBD) are infections that are transmitted to humans through the bite of an infected arthropod such as mosquito or tick West Nile Virus Lyme Eastern Equine Disease Encephalitis Zika Tome, 2020  West Nile Virus first recognized in Africa in the 1930s circulates between birds and bird-biting mosquitoes (i.e. amplification vectors) species of mosquitoes that transmit the virus from birds to humans or horses are called bridge vectors: in Ontario, Culex pipiens and Culex restuans, both common in urban areas first detected in New York in 1999 and since then has spread across most of North America. WNV was first detected in Ontario in birds in 2001, with the first human cases the following year WNV infection in humans first became a disease of public health significance in Ontario in 2003. Russell and Nelder, 2019: https://www.publichealthontario.ca/-/media/documents/v/2019/vector-borne-diseases-2018.pdf?la=en  Mosquitoes West Nile Virus, Eastern Equine Encephalitis and Zika are all viruses Severe cases symptoms: Brain inflammation Muscle weakness Paralysis Death Flu-like symptoms: Fever Headache Body Aches Fatigue 10 Tome, 2020  West Nile Virus https://www.publichealthontario.ca/en/data-and-analysis/infectious-disease/west-nile-virus Framing (Problem Identification) Nature of the condition - Potential or available test - Alternative policy options Risk to blood supply (i.e. Krever Commission) Zero tolerance – Precautionary Principle Costs of doing something vs. not doing something: such argument places a dollar value on human life Understanding the Nature of the Problem Knowing what we know, and more importantly, what we do not know! How do we ‘keep on top’ of emerging issues Once identified, are there potential or available tests Plans in place to act quickly in the event of an emerging problem (e.g. pandemic planning) Alternative policy options Precautionary Principle Action should be taken to prevent serious potential harm, regardless of scientific uncertainty as to the likelihood, magnitude, or cause of that harm. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1278478/ Rio Declaration 1992 - Principle 15 – “In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost- effective measures to prevent environmental degradation”. Precautionary Principle Point at which human well-being and environmental health are put at risk by activities that we can control Once identified, “a course should charted, and precautionary actions taken to ameliorate or prevent a potential threat to human and environmental health on behalf of current and future generations” (UNCED Rio Declaration, 1992) Precautionary principle affords humanity a mechanism to “engage in the regulation of behaviors that are advantageous rather than detrimental to human and environmental health. As a mechanism of science, the precautionary principle becomes a useful tool in raising awareness and determining aspects of human culture that are and are not sustainable”. (UNCED Rio Declaration, 1992) Precautionary Principle Principles Proportionality - tailoring measures to the chosen level of protection. Non-discrimination - comparable situations should be treated in the same way unless there are grounds for doing so. Consistency - measures should be of comparable scope/nature to those already taken in similar areas where scientific data are available. Examining costs and benefits - comparing costs of action and lack of action in both the short and long term; not just an economic cost- benefit analysis Subject to review in light of new scientific data – when applied, the chosen level of protection should be maintained so long as scientific information is incomplete or inconclusive and the risk to public health (Weir et. al. 2010 https://europepmc.org/article/med/21214055 ) Precautionary Principle in Principle If hazards are well established and supported by scientific evidence, precautionary action is almost always going to receive consensus support “When there are significant gaps in the scientific understanding of hazards, precautionary regulatory policies and recommendations to consumers are often controversial”. (Beloin, 2009) Risk Management Science “the systematic scientific identification, evaluation, and prioritization of risks of adverse health effects resulting from human or environmental exposure to hazardous agents or situations, and the economical application of resources to minimize, monitor, and control the probability and/or impact of the adverse events.” Haschek and Rousseaux's Handbook of Toxicologic Pathology (Third Edition), 2013 UCI Division of Continuing Education, 2017 Failure Modes & Effects Analysis Steps in the process Failure modes (What could go wrong?) Failure causes (Why would the failure happen?) Failure effects (What would be the consequences of each failure?)  Failure Modes & Effects Analysis https://quality-one.com/fmea/ What’s blood got to do with these approaches to policy? Krever Commission Final report produced in late 1997 How Canada’s blood supply system managed the threat of Hepatitis C and HIV via blood transfusion Argued to be the largest public health catastrophe in Canadian history 1000 – HIV, and 30,000 Hep C via transfusions in the late 1970s and 1980s Reformed blood system has been seen as a success particularly with respect to how it keeps us safe from bloodborne infections “un-‐priced, unintentional and uncompensated side effect of one agents’ action, that directly affects the welfare of another (Baumol and Oates 1998; Sundqvist 2004).” Two aspects of the report are esp. important: precautionary measures and creation of a governance system that prioritizes safety CBS has responded since with CJD and WNV; principles applied to SARS and to a large extent, COVID 19 Wilson, 2007; https://www.cmaj.ca/content/177/11/1387 Krever Commission & the Naylor Report The Naylor Report examined the reactions to SARS (National Advisory Committee on SARS & Public Health, 2003) public health policies in Canada are strongly affected by intergovernmental relations. “existing allocation of responsibilities across various levels of government has led to considerable confusion as to who should be doing what, and that the resulting gaps and overlaps can endanger the public health of other jurisdictions, since infectious disease tends not to respect jurisdictional boundaries”. (Naylor, 2003) Public Health Renewal in Canada (Naylor, 2003) Constitutionally, public health is primarily a provincial concern, although it is actioned at the municipal level federal government has authority to legislate aspects of public health over matters related to the maintenance of "peace, order and good government”, including quarantine provisions and national borders, and trade and commerce of an interprovincial or international nature. “Behind the formal division of powers is an essential tension in the Canadian F/P/T fabric: much administrative responsibility rests with the P/T level, while revenue generation and therefore spending capacity is concentrated at the federal level”. Public Health Renewal in Canada “We learned very rapidly that Canada’s ability to fight an outbreak such as SARS was tied more closely to the specific strengths of our public health system than to the general capacity of our publicly-funded personal health services system. By public health, we refer to systems that are population- focused, and include functions such as population health assessment, health and disease surveillance, disease and injury prevention (including outbreak or epidemic containment), health protection, and health promotion. Our analysis and our recommendations accordingly set out a plan for a comprehensive renewal of both the public health systemin general, and the nation’s capacity to detect, prevent, understand, and manage outbreaks of significant infectious diseases”. (Naylor Report, 2003) What pieces do we select? HOW DO WE SELECT THEM? Trade offs “The first rule of economics is that there is an infinite number of desires chasing a finite number of goods, services and resources…” Thomas Sowell “…The first rule of politics is to ignore the first rule of economics.” …also Thomas Sowell Cost – Economic Evaluation In economics, costs aren’t just measured in monetary terms, but in terms of opportunity costs: “The true cost of something is what you give up to get it.” http://www.economist.com/ The perspective of an economic evaluation is the answer to the question, “Whose costs are included?” Hospital (or other health organization) Healthcare system/Healthcare payer (e.g. include health care costs incurred in multiple organizations) Health system (Costs in health and other sectors, e.g. Social Services, Environmental, Transportation) Societal (All costs, including patient costs) Externalities What is a Cost? Direct Indirect – lost wages Intangible – Pain, suffering, or opportunity Recall Effects & Implementation... Economic evaluation “The comparative analysis of alternative courses of action in terms of both their costs and consequences.” Methods for the economic evaluation of health care programmes, Drummond et al. WHY would we do this? Opportunity Cost Economic evaluation … is always comparative At least two options are compared Analyses with only one option are called descriptive studies One of the comparators can be “no therapy” One of the comparators can be “the status quo” … always involves costs … each type measures the consequences or outcomes in different ways Cost Analysis or Minimization Efficacy of A and B are the same Cost is the only difference A B Cost Effectiveness Evaluation Natural Units # heart attacks reduced Intervention A # Cancer cases avoided Intervention B # kilograms lost Intervention C Reduction in Blood pressure Life years gained Cost Effectiveness Evaluation (Jean Baptiste, 2017)  Cost Utility Evaluation Interventions with different health outcomes - QALY Uses a QALY or health utility measure to evaluate cost/QALY https://en.wikipedia.org/wiki/Quality-adjusted_life_year  Cost Benefit Analysis Compares ALL costs (incl. Intangible) and ALL benefits o e.g. WTP, human capital Very comprehensive and difficult (and often fraught with ethical issues) In practice, CBA and others involves stratification, discounting, and sensitivity analyses (Jean Baptiste, 2017) Ethical Decision Making Structural Functionalism Precautionary Principle Virtue Ethics & Deontological Principilism? The ”big 4” apply in most every policy decision Utilitarian? Cost analysis is very utilitarian! Related/Support readings in Chapter 1 2.1.3 Federal vs. Unitary models 2.2.1 Federalism in Canada: The Constitution Act, 1867 3.4 Framing 3.6.2 The Precautionary Principle 6.3.1 Public Health 7.2 Canada Health Act 8.1 Economic Analysis: Cost-effectiveness 8.2 Screening